Transistors go ballistic

Computer designers at the University of Rochester are developing a “ballistic deflection transistor”, which uses electrons’ inertia to direct their paths, using much less energy.

The amount of heat current transistors generate and the electrical "leaks" in their ultra-thin barriers have already begun to limit their speed. The ballistic deflection transistor (BDT) bounces the electrons into their chosen trajectories, using inertia to redirect them for "free," instead of using energy to wrestle the electrons into place.

The BDT should produce far less heat and run far faster than standard transistors because it does not start and stop the flow of its electrons.

The researchers say it resembles a road intersection with a triangular block. From the "south" an electron is fired, as it approaches the crossroads, it passes through an electrical field that pushes the electron slightly east or west. When the electron reaches the middle of the intersection, it bounces off one side of the triangle block and is deflected straight along either the east or west roads.

In this way, if the electron current travels along the east road, it may be counted as a zero, and as a one if it travels down the west road.

The BDT design should be able to resist much of the electrical noise present in all electronic devices because the noise would only be present in the electrical "steering" field, and calculations show the variations of the noise would cancel themselves out as the electron passes through.

The BDT is named "ballistic" because it is made from a sheet of semiconductor material called a 2D electron gas, which allows the electrons to travel without hitting impurities, which would impede the transistor's performance.